Folding and guiding mechanism for double wall bag machines



Sept. 11, 1956 C. B. HARKER FOLDING AND GUIDING MECHANISM FOR DOUBLEWALL BAG MACHINES 3 Sheeis-Sheet l VMIIIIIIII'IIIIII Filed NOV. 26, 1952Sept. 11, 1956 c. B. HARKER 2,

FOLDING AND GUIDING MECHANISM FOR DOUBLE WALL BAG MACHINES Filed NOV.26, 1952 3 Sheets-Sheet 2-=IIlIl!l!IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII W V A =3 f i NVESMTOM p1, 1956 c. B. HARKER 2,762,273

FOLDING AND GUIDING MECHANISM FOR DOUBLE WALL BAG MACHINES Filed NOV.26, 1952 3 Stunts-Sheet 3 W max,

Chowlec q-(czv Rev United States Patent*() FOLDING GUIDING IVIECHANTSMFOR DOUBLE WALL BAG MACHINES Charles B. Harker, Rockford, Ill., assignorto Bartelt Engineering Company, Rockford, 11]., a corporation ofIllinois Application November 26, 1952, Serial No. 322,726

4 Claims. (Cl. 93-20) This invention relates to machines for makingdouble wall bags and, more particularly, to a machine in which the bagsare formed in a series by folding two strips longitudinally, one insidethe other, and then sealing the strips transversely at spaced intervals.

The general object is to provide in a machine of the above character anew and improved mechanism for foldmg the strips neatly with the twostrips positioned accurately relative to each other.

A more detailed object is to control each strip individually as it isbeing folded by using separate sets of rollers to tension the stripsabout the folding mechanism.

Another object is to provide two formers, one in the path of each strip,so that each strip is folded separately thereby effecting a neater andmore accurate fold.

The invention also resides in the novel means by which the strips areheld out of contact with each other until they are ready to be sealedtogether so that the two strilps may be guided individually into the bagforming pat 7 Other objects and advantages of the invention will becomeapparent from the following detailed description taken in connectionwith the accompanying drawings, in

' which Figure l is a fragmentary side elevation with parts broken awayof a bag making machine embodying the novel features of the presentinvention.

Fig. 2 is an enlarged fragmentary sectional view taken along the line 22in Fig. 1.

Fig. 3 is an enlarged fragmentary sectional view taken along the line 33in Fig. 1.

Fig. 4 is a plan view of the folding mechanism.

Fig. 5 is a sectional view taken along the line 55 in Fig. 4.

. As shown in the drawings for the purpose of illustration, theinvention is' embodied in a machine for making double wall bags, thatis, bags which have a liner insidethe outer lbag walls. Bags of thistype may be made on a machine similar to the'one shown in the copendingapplication'of Harold L. Bartelt, Serial No. 98,660, filed June 13,1949, now Patent No. 2,649,674, to which reference may be had forfurther details. In general machines of this type form bags in a seriesby folding a strip of liner material and a strip 11 of wall materiallongitudinally with the liner strip inside the fold of the wall stripand then sealing the two strips together transversely at equal intervalsas indicated at 12.

In the present instance, the strips 10 and 11 are drawn ofi supply rolls13 and 14, which are mounted on the frame 15 of the machine, by feedrollers 16 engaging the folded strips and driven intermittently througha suitable indexing mechanism 17 by a motor 18. From the supply rolls,the strips are threaded around a series of guide rollers, indicatedgenerally at 19, and are advanced across a folding mechanism 20 whichfolds the strips. The folded strips pass between idler rollers 21 andthen the seal 12 is formed during a dwell of the strips by heated shoes22 operated from a camshaft 23 driven by the -motor 18.

Patented Sept. 11, 1956 To effect a more accurate fold, the presentinvention contemplates the provision of a novel folding mechanism 20 inwhich the two strips 10 and 11 are held individually about the foldingmechanism, and thereby are controlled individually, by separate sets oftensioning rollers 24 and 25. Preferably, the folding mechanismcomprises two formers 26 and 27, one inside the other and each disposedin the path of one of the strips so that the strips are foldedseparately about individual formers and the outer former 27 serves as acommon backing member for both sets of rollers 24 and 25. Thus, therollers 24 are disposed within the fold and press the liner strip 10against the inside of the former 27 while the rollers 25 hold the outerwall strip 11 against the outside of this former.

Herein, the inner former 26 comprises two triangular side plates 28mounted on the frame with their apexes spaced apart laterally andlocated to be engaged first by the liner strip 10 as the latter isadvanced by the feed rollers 16. The plates converge in the direction ofadvance of the strips meeting, as shown in Fig.2, adjacent the idlerrollers 21 and are joined together by a triangular bottom plate 29 whichspans and is secured as by welding to the lower edges of the side plates28. To form the outer former 27, a second set of generallytriangularplates or members 30 are bolted to the outside of the plates 28 and heldslightly away from the latter by spacers 31 so that the liner strip 10may pass between the plates 28 and 30 as shown in Fig. 3.

Each of the rollers 24 and 25 is tilted upwardly as shown in Fig. 1 sothat it tends to draw the side edge of the strip which it is engagingupwardly thereby drawing the strip around its former. The inside rollers24 are disposed near the rear of the former 26 with one alongside eachof the side plates'28 and each projecting through a hole 32 in theadjacent plate as shown in Fig. 3 so that they may engage the linerstrip and press it against the side plate 30. The outer rollers 25 aremounted near the front of the folding mechanism 20 and cooperate withthe plates 30 in a similar manner to hold the wall strip around theformer 27.

To support the inner rollers 24, a framework 33 is mounted on the upperends of posts 34 and 35 upstanding from the frame 15 and the rollers arejournaled on the forward ends of arms 36 which are pivoted intermediatetheir ends on a transverse bar 37 of the framework. A contractile spring38 acting between the rear ends of the arms 36 urges the rollers 24outwardly against the inner surface of the liner strip 10. Each of theouter rollers 25 is journaled on an arm 39 which is clamped for verticaladjustment to a rotary sleeve 40 on the forward post 35. On each side ofthe folding mechanism 20 is a vertical rod 41 which is fixed to a collar42 on the lower end of the corresponding sleeve 40 and projects upthrough a hole in the arm '39 and above the top of the plates 28 and 30.Acting between the upper ends of the rods 41 is a second contractilespring 43 urging the rollers inwardly against the wall strip 11.

With the foregoing arrangement, the liner strip 10 passes around theinner former 26 and between the side plates 28 and 30 while the outerwall strip 11 is advanced along the outer former 27 outside the plates30. Due to the action of the springs 38 and 43, the inner rollers 24 areurged outwardly through the holes 32 in the plates 28 and hold the edgeportions of the liner strip against the insides of the plates 30 and theouter rollers 25 are biased inwardly holding the wall strip against theoutside of these same plates. As the feed rollers 16 draw the stripsacross the folding mechanism, the rollers, due to the upward tilt, tendto urge the edge portions of the strips upwardly thus tensioning eachstrip about its respective former so that the two strips are foldedprogressively, one inside the other.

In accordan ce with another aspect of the invention, H

the strips and 11, as they are unwound from their respective supplyrolls 13Yand 14, are advanced along substantially independent-pathsunti-l they are ready to be joinedtogetiier by the sealing .shoe 22 sothat each strip may be guided individually and accurately into bagforming path. To this end, the supply rolls are mounted independentlyand the guide rollers 19 are arranged in a novel manner to provideseparate rollers for each strip. Thus, the supply roll 13 of liner material is carried on the outer end of a support 44 projecting rearwardlyfrom the machine frame and the liner strip 10 is threaded up around aroller 45 mounted on the outer ends of arms 46 which are fixed to andproject rearwardly from the posts 34. From the roller 45, the linerstrip passes down around a roller 47 journaled on arms 48 below thearms; 4d, then up around a roller 49 on the arms 46 inside the roller 45and then across the former 26.

' The supply roll 14 of wall material is mounted on a separate support50 which is fixed to the frame 15 below the support 44 and the strip 11,as it is unwound from the roll, passes up along the inside of a roller51 journaled on the upper support 44 and then up over a roller 52 on thearms 46 inside the roller 49. From the roller 52,

the strip travels across the former 27. Asshownin Fig. 1, the positionof the rollers 49 and 52 is such that the two strips approach theirrespective formers along spaced paths 7 It will be observed that thestrips 10 and 11 are folded separately about independent formers 26 and27 and each is held about its respective former by a separate set ofrollers. Thus, the two strips are folded individually and the resultingfold is neat and accurate. In addition,

the" strips are guided along separate paths by the guide.

rollers 19 and do not contact each other until just before they aresealed together. Although the strips may weave slightly before beingfolded, therefore, weaving of one will not affect the .alinement of theother. Thus the strips when folded will be disposed properly relative toeach 1 other and the bags will be properly formed and neat inappearance.

I claim as my invention:

1. Mechanism for folding two strips of material, one

inside the other, said mechanism comprising, two triangu;,

lar plates spaced apart at their .apexes and converging toward theirbases, a pair of flat generally triangular backing members, one disposedalongside but spaced from the outer surface of each of said plates, afirst pair of rollers disposed between said plates, each of said plateshaving a hole adjacent one of said rollers, a second pair of rollersdisposed outside said backing members, and 5 spring means urging saidsecond rollers inwardly against the outer surfaces of :said backingmembers and said secondrollers outwardly through said holes and aganistthe inner surfaces of the backing members.

2. In :a bag making machine, the combination of, mechanism forsupporting and advancing longitudinally two strips of material disposedside by side, a first former disposed in the path of advance of a firstone of said strips and operable to fold said first strip, a secondformer mounted exteriorly of said first former and in the path of thesecond strip to fold the latter whereby said first strip passes betweensaid formers and said second strip passes on the outide of said secondformer, said first former having holes therein, a first set of rollersmounted inside said first former .and projecting through said holes to'hold said first strip against the inside wall of said second former andtension the strip around said first former, and a second set of rollersdisposed exteriorly of said second former and acting to tension thesecond strip around the same.

3. In a bag making machine, the combination of, mechanism for supportingtwo strips of material disposed side by side and advancing the sameendwise along predetermined paths, a folding device disposed in saidpaths and operable to fold said strips longitudinally one inside theother, a first set of rollers disposed inside the fold and engaging theinner strip to tension the latter around said folding device, and asecond set of rollers mounted.

outsid of the fold and engaging the outer strip to tension the sameabout said folding'device, said folding device including rigid partsdisposed outside said inner strip adjacent saidfirst rollers toconstitute .a backing for the latter and rigid parts disposed adjacentsaid second rollers and inside the outer strip to'provide a backing forsaid second rollers. a j

I 4. In a bag making machine, the combination of, a folding device, twoflat backing members, one mounted at each side of said device, mechanismforsupporting two strips of material disposed side by side and advancingthe strips longitudinally across said device to fold the strips,longitudinally'with the edge portions of one strip passing across theinner sides of said members and the edge portions of the other strippassing across the outer sides .of the members, a first set of rollersdisposed between said members with each adjacent one member'and eachoperabl to press the inner strip against the adjacent member to hold thestrip about said folding device,.and a second set of rollers mountedexteriorly of said members andoperable to press the outer strip againstthe members and hold that strip about said folding device.

References Cited in the file of this patent UNITED STATES PATENTS BakerSept. 3, 19.35

